Power semiconductor devices such as IGFETs (insulated gate field effect transistors) and IGBTs (insulated gate bipolar transistors) are typically vertical devices with a load current flow between a first surface at a front side of a semiconductor die and a second surface at a rear side. In a blocking mode, stripe-shaped compensation structures extending from the front side into the semiconductor die deplete a drift zone in the semiconductor die. The compensation structures allow higher dopant concentrations in the drift zone without adverse impact on the blocking capabilities. Higher dopant concentrations in turn reduce the on state resistance of the device.
It is desirable to provide reliable semiconductor devices with low ohmic losses.